Conventionally, the stopper member is shaped so that, when it is lifted it is moved to a fully raised position and remains in that position by its cooperation with the water in the tank until all of the water is discharged where upon a stopper member is moved by gravity back to the closed position.
This cooperation has conventionally been used to ensure that a full quantity of the flushing water is discharged to ensure a proper flushing action. This design was generated at a time when concern for the water supply was at a minimum so that a full discharge was much preferred at each flush with the concentration being on ensuring a proper flushing action rather than minimizing the quantity of water used. Toilets of this design are therefore in wide use in large numbers in homes throughout North America.
Attempts have been made to reduce that quantity of water released in the flushing action by providing weights which rest against the stopper member to provide an increased downward force on the stopper member so that it returns to the closed position before the level of the water drops to the normal minimum position. In one example a weight is engaged over the stopper member and remains in position on the stopper member to move the center of gravity of the stopper member. This arrangement is proposed generally for use with the style of flushing action manufactured by American Standard.
In an alternative arrangement in which the toilet includes a vertical over flow pipe, a sliding weight is provided which runs up and down the vertical pipe and is arranged to fall and hit the stopper flap when the water level falls to a lower position.
None of these weight type devices allows the user to effectively control the amount of water flushed since the stopper member moves by the lever action to its normal fully open position allowing the discharge of water and then is moved to the closed position after discharge of a smaller quantity of water than is normally discharged. The user cannot therefore easily control the amount of flushing water from a very small quantity for a small flush or up to the maximum quantity for a larger flush if required in a particular circumstance.